Organotypic Rat Tissue Models for Translational Toxicity Assessments

AbstractThe goal of the current Phase I SBIR project is to develop commercially scalable and reproducible in vitrodimensional organotypic models of rat tissues including airwaybronchial and alveolarintestine and liverThese models will replicate biological responses of the corresponding in vivo rat tissues and provide an alternative to traditional in vivo rat toxicity testingThe speciesratand organ tissueslungliver and intestinewere chosen as initial models for commercial development in the current project based on specific stated interests of the funding agency and requests of prospective pharmaceutical industry customersThese ratderived in vitro models will provide in vitro to in vivo translational information needed to predict toxicity of chemical and drug candidates by allowing for comparisons with existing in vivo rat dataThese models will also enable comparisons with existing human cell based in vitro organotypic models that use similar technologiesThe translational information provided by these models will ultimately improve confidence and facilitate use of in vitro models for predicting human clinical outcomesThe Specific Aims of the Phase I project are as followsAimDevelop organotypic rat bronchial and alveolar airway epithelial modelsAIMDevelop organotypic rat Intestine epithelial modelsThe airway and intestine models will be cultured on microporous membrane inserts at the air liquid interfaceAIMDevelop organotypic rat liver modelsThese will consist of hepatocytes and hepatic stellate cells co cultured as spheroidsAIMDemonstrate the interaction of intestine liver and airway liver models in pilot experiments using a perfused multiorgan chipMOCTroglitazonean anti diabetes drug that was withdrawn from the markets due to severe liver injurywill be used as a model drug to evaluate liver toxicity following delivery via the intestinaloralor alveolarinhaledepitheliumIn Phase IIthese models will be further evaluated in microphysiological MOC experiments to validate more complex multi organ interactions and toxicological effectsAddition of immune componentsmacrophagesdendritic cellsKupfer cellswill also be undertake during the Phase II periodSpecific endpoints to be evaluated in the current work include tissue viability assessmentsbarrier disturbancedrug transport and or metabolismfibrotic responsesand innate immune responsesThe results of the in vitro experiments conducted in the current project will be compared to existing historical data previously reported for in vivo animal studies and human clinical datae gplasma concentrations following oral absorptionand known toxicological effects of drugsIndustry and government regulatory agencies are seeking the development and evaluation of methods for replacement or reduction of animal use in toxicity testingAlternative in vitro organotypic culture modelsOCMshave potential for meeting the goals of reducing animal use as well as reducing the cost and time required for drug and toxicant screeningAnimal based in vitro systems that complement current in vivo animal tests and in vitro human test systems will provide an opportunity to develop an understanding of how to extrapolate in vitro biology to in vivo biologyleading to decreased reliance on in vivo animal models for future testingTo facilitate attainment of this goalthe current project proposes to develop and characterize in vitro OCMs of rat lungliver and intestineAs proof of conceptinteraction of these key organ systems with regard to drug transportmetabolism and toxicity will be evaluated in multi organ chipMOCexperimentsThe availability of animal cell based organotypic models will further help toxicologists in understanding the translational ability of the animal and human cell based in vitro models to predict effects in humans